Keep getting Error 24 on different pc's

[Sukhy13e13]

Hi, I'm keep getting Error 24, whenever I run a unlocker. I tried it on two Win7 pc, and xp too

here's the log:
DC - Unlocker 2 Client 1.00.0575

Detecting phone :

selection :
manufacturer - Huawei phones
model - Auto detect (recommended)

Found Phone : 19
Model : Huawei U7510/U7517/U7519
IMEI : 356192034003033
Firmware : APP-U7519V100R001CANC98B549SP01-SEC-DEBUG-NOLOG

================================================== =================

Unlocking, please wait ...

Preparing Boot Download mode ...

unlock failed !

(error code 24)

[Vincentas]

Something is taking the port. Check, if no other modems or phones are connected to computer at unlock time.
Be sure phone software is closed at unlock time.
Also, check, if all drivers are installed.
Also you can try unlocking again. Unlocking same device again does not require credits.